Tag: planets and stars

Questions Related to planets and stars

Surface gravity of different planets in correct decreasing order is

  1. Neptune, Jupiter, Saturn, Earth

  2. Jupiter, Neptune, Earth, Saturn

  3. Jupiter, Neptune, Saturn, Earth

  4. Jupiter, Uranus, Neptune, Saturn


Correct Option: C
Explanation:

Surface gravity of different planets has a unique surface gravity.
Newton's second law of motion: $F=ma$............(1)
Law of universal gravitation: $F _g=\dfrac{GM _1M _2}{R^2}$............(2)
The value of $G$ was originally determined experimentally by Henry Cavendish and has a value of $6.67\times10^{11} N m^3/kgs^{2}$
By using these two equations, one can derive another equation that shows the acceleration due to gravity at the surface of a planet, i.e., $g=\dfrac{GM}{R^2}$
Where $M$ is the mass of the planet and $R$ is its radius.
The surface gravity of the planets, as determined by the equation above and shown relative to Earth's gravity can be seen below:

Object:           g/g-earth:       Acceleration at the surface

Earth...............$1.0$...............$g = 9.78\ m/s^2$ ($32.1\ ft/s^2$)

Jupiter.............$2.36$...........$g = 23.1\ m/s^2$ ($75.9\ ft/s^2$)

Saturn.............$1.07$.............$g = 9.05\ m/s^2$($29.4\ ft/s^2$)

Uranus............$0.889$...........$g = 8.69\ m/s^2$($28.5\ ft/s^2$)

Neptune..........$1.12$.............$g = 11.0\ m/s^2$($36.0\ ft/s^2$)

So, surface gravity of different planets in correct decreasing order is Jupiter, Neptune, Saturn, Earth.

Pluto is to Yam, as Venus is to

  1. Shukra

  2. Mangal

  3. Shani

  4. lndra


Correct Option: A
Explanation:

Hindi name for Pluto is yam and for Venus is Shukra. 

Varun is the Indian name of the

  1. Pluto

  2. Jupiter

  3. Uranus

  4. Neptune


Correct Option: D
Explanation:

Ans: Neptune

The planet farthest from the Sun is

  1. Mercury

  2. Venus

  3. Neptune

  4. Earth


Correct Option: C
Explanation:

Planet farthest from sun is Neptune.

Ans: Neptune

The outermost layer of the Earth is called

  1. crust

  2. mantle

  3. core

  4. none of these


Correct Option: A
Explanation:

Outermost layer of earth is called Crust.

Other layers are mantel, outer and inner core.
Ans: Crust

The hottest planet of the solar system is

  1. Mercury

  2. Neptune

  3. Jupiter

  4. Venus


Correct Option: D
Explanation:

Venus is the hottest planet. Although its not the closest to the sun, its dense atmosphere traps heat and warms it.

Ans: Venus

The temperature of the centre of the Earth is about

  1. $4000^oC$

  2. $6000^oC$

  3. ${10^4 }^oC$

  4. ${10^6 }^oC$


Correct Option: B
Explanation:

Temperature of center of earth is 6000 degree celsius.

Ans: 6000 degree Celsius.

Mercury and Venus, both, do not have any

  1. atmosphere

  2. solid matter

  3. satellite

  4. fixed orbit


Correct Option: C
Explanation:

Mercury and Venus have no natural satellites. they are both inner planets and inner planets tend to have very few or no satellites and rings.